rogers



2 Sheets Sheet 1 C. D. ROGERS.

DIEA POR FOEMING SCREW HEADS.

Patented Sept. 4, 1888..

2 Sheets-Sheet 2.

(No Model.)

C. D. ROGERS.

DIE PoR PORMING SGREW HEADS.

No. 389,167. Patented Sept. 4, 1888.

INVENTEIH' W ITNE EEE.

UNITED STATES PATENT EEICE.

CHARLES D. ROGERS, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR IOTHE AMERICAN SCREW COMPANY, OF SAME PLACE.

DIE FOR FORNlNG SCREW-HEADS.

SPECIFICATION forming part of Letters Patent No, 389,167, dated September 4, 1888.

Application filed July/,1887. Serial No2-13,674. (No modell) To all whom t may concern:

Beit known that I, Cr-rARLEs D. RocERs, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Hammers for Forming the Heads of Screws; and I do hereby declare the'following to be a full,clear, and exact description of the invention, such as 1o will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or gures of reference marked thereon, which form a part of this specification.

r 5 My invention relates to improvements in headinghammers employed in `forming the .heads of screws.

In an application for a patent filed simultaneously herewith, Serial No. 243,67 2,1 have .Q0 described a method for making finished heads for screws by forging alone,and in another application, Serial No. 243,657, I have described a machine employing three hammers for forming screwheads,wbich is adapted especially to forging heads of a larger diameter relatively to the wire from which they are forged than has heretofore commonly been done.

In the process described in the first applicacation the slot in the head of a screw is formed 3o by a tongue extending from the face of the hammer which finishes the head. This tongue is forced into the metal in advance of the action of the flat surface of the hammer upon the metal, and forms an obstacle to the liow of the metal from one side of the die to the other. It is important, therefore,that the metal,before this hammer acts upon it, shall be distributed symmetrically with reference to the slot upon the two sides of the die. Agan,it is obvious 4o that the tongue, as it is forced into the metal, must spread the metal laterally; but at the ends of the tongue it docs not force the metal freely toward the conical surface of the die, but has a tendency to carry it downward,so as to produce an imperfect face at the ends of the slot. This tendency showsitself most decidedly in making heads of a larger diameter across the face than has been commonly practiced heretofore, and must be met by securing a 5o proper distribution of the metal in the die bcfore the hammer acts upon it, and these rcquirements must be provided for in one or more of the hammers which are brought into action before the finishing-hammer.

To attain these requirements is the object of the present invention, illustrated in the accompanying two sheets of drawings,in'which Figure l is a perspective View representing a screW-head having the nick extending entirely across its face. Fig. 2 is a similar view of a 5o screw-head in which the slot is closed at each end. Fig. 3 is a perspective view of .a screw-head, showing the tendency of the metal to be forced downward at the ends of the slot by means of the tongue of the nick-swag ing hammer, as referred to in the preceding paragraph. Fig. 4 is avertical sectional view taken through the center of the die and the lower portion of the first headinghanuner,and also showing a wire in position to be upset. 7o Fig. 5 is a similar sectional View showing the metal upset,thereby producing a symmetrical preliminary head. Fig. 6 is a perspective View showing a concave groove extending across the face of the second hammer. Fig. 7 75 is a transverse sectional view thereof, taken through its center. Fig. 8 is a vertical cen tral sectional view of the die and a second hammer, showing the upper face of the head ofthe blank made somewhat rounded and con- 8o forming to the shape of the hammer-face. Fig. 9 is a similar view of the parts, viewed at right angles to the former position. Fig. 10 is a perspective view showing the workingface of the third or slotting hammer. Fig. l1 S5 is a vertical central sectional view of the hammer. Fig. 12 is a perspective View of another second hammer, showing a convex or cylindrical projection extending partially across its face in lieu of the concave groove shown in 9o Fig. 6; and Fig. 13 is a sectional view corre spending to Fig. S, showing the hammer represented in Fig. 12 impressed into the metal and disposing the same immediately preceding the action of the slottinghammer.

lThe following is a detailed description of my improvement in the manufacture of wood screws:

I would state that the finished screw-head a (represented in Fig. 2) is constructed in acroo cordance with my present invention, while the head ai (shown in Fig. 3) represent-s an effect which may be produced by hammers unprovided with such improvement, wherein the metal fails to properly fill the cavity of the stationary die, thus forming the indentations or depressions d at the ends of the slot.

In the several figures the form of the diecavity is represented conical, as at c.

A indicates the die-block itself.

The first hammer, h, that I employ does not differ in construction or in its action from that heretofore employed in the first operation of forging heads in a die with two hammers only, as commonly used. The face of the hammer has in it a conical cavity, e, terminating at its upper end in a cylindrical portion, into which the end of the wire b enters as the hammer approaches it, (see Fig. 4,) the wire at the same time being firmly clamped in position. This cavity furnishes a lateral support to the end of the wire and prevents it from bending out of its axial line. The manner in which it upsets the metal and partially fills the diecavity c is shown in Fig. 5, the upset metal of the wire being indicated by b. By this operation the metal is symmetrically arranged with reference to the surface of the die and leaving an unfilled space,e, but in theoperation of the second hammer, t', where three are used and a slot is to be formed, it is necessary that the metal of the head shall be disposed symmetrically on the two sides of the line where the slot is to be formed, and at the same time provision must be made to fill the die at the ends of the slot. The danger of an unsymmetrical disposition of the metal in the die increases as the diameter of the face of the head increases relatively to the diameter of the wire, and the object I have in view is to counteract this tendency. The best form which I have found to effect these objects is shown in Figs.

6 and 7, wherein I have represented the second hammer, i, having a concave depression,

m, cut across its face.

Figs. 8 and 9 represent views cut, respectively, transversely and longitudinally of the concave depression `of said secondhammer, and also showing at b2 the corresponding form of the head. It will be observed, referring to Fig. 8, that a space, c2, is left unfilled by the Vmetal at opposite sides of the die, but are nearly filled in the line of the depression, as in Fig. 9, which coincides with the axis of the slot when the latter is formed. The third or slot forming and finishing hammer is indicated by s, Figs. yl0 and 11, its fiat face having a tongue, t, projecting from it, adapted to form the slot or nick in the head of the blank and producing the slotted and finished head a shown in Fig. 2. The concave depression m of the second hammer when acting on the metal allows it to flow more freely toward the ends of the depression than across it, and thus insures the necessary amount of metal at the ends of the tongue, which in the succeeding hammer forms the slot. The concave surface also tends to check any tendency the metal may have to flow to one side of the line in which the slot is to be formed rather than to the other, and thus secures as far as required the symmetrical distribution of the metal on the two sides of such line.

Another form which maybe given to the face of the second hammer, i, is represented in Figs. l2 and 13. Practically, however, I prefer the form shown in Figs. 6 and 7. The former differs from that shown in the latter figures in having a rounded projection, r, extending across a portion of the face of the hammer at right angles with the line in which the slot is to be formed, instead of a depression in the line of the slot; but, like that, it has these features in common, that the metal is symmetrically arranged with reference to the line of the slot, and it provides for the necessary amount of metal at the ends of the tongue t, which in the succeeding hammer forms the slot. 'Ihe surface of the convex projection r across the line of the slot acts in a manner analogous to a concave surface in the line of the slot to secure the condition required to enable thesucceed'ing hammer to form the slot and finish the head.

The depth or'width of the concave depres sion required will vary with the size of the heads and the depth and width of the slot according to the character of the metal operated on, and can be most easily determined as to any particular screw-head by trial, and the same is true of they convex surface when that is used.

l. The heading-hammer for preparing the head of a blank for the action of a finishing and slotting hammer, the acting part of the face of which is slightly curved or cylindrical, substantially as herein described. f

2. rIhe combination, in a machine for forming finished heads of fiat-headed screws, in-

cluding the slot, of two heading-hammers, the` IOO IIO 

